Compensated Compactness, Separately convex Functions and Interpolatory Estimates between Riesz Transforms and Haar Projections

Jihoon Lee, Paul F. X. Müller, and Stefan Müller

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Submission date: 31. Jan. 2008
Pages: 52
published in: Communications in partial differential equations, 36 (2011) 4, p. 547-601 
DOI number (of the published article): 10.1080/03605301003793382
Bibtex
MSC-Numbers: 49J45, 42C15, 35B35
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Abstract:
In this work we prove sharp interpolatory estimates that exhibit a new link between Riesz transforms and directional projections of the Haar system in To a given direction we let be the orthogonal projection onto the span of those Haar functions that oscillate along the coordinates When the identity operator and the Riesz transform provide a logarithmically convex estimate for the norm of see Theorem 1.1. Apart from its intrinsic interest Theorem 1.1 has direct applications to variational integrals, the theory of compensated compactness, Young measures, and to the relation between rank one and quasi convex functions. In particular we exploit our Theorem 1.1 in the course of proving a conjecture of L. Tartar on semi-continuity of separately convex integrands; see Theorem 1.5.